No mystery with A Series regrinds, any competent machine shop could do it, the cranks follow normal automotive practice. As GB mentioned, the radius where pin meets web is important, and printing off the service sheet and showing it to the grinder may go a long way to getting what you want. The radius is determined by the dressing of the grinding wheel, and you can bet the majority in this business will assure you it's gonna be fine, using the same wheel for any crank that comes through the door. As a punter, how are you going to check?
Flywheel can stay on, but important to strip out the sludge trap etc before it goes for grinding, thus avoiding damage to your newly ground crank pins as you struggle with the plugs. No if's or but's, a clogged up trap will wreck all your expensive handiwork in minutes. Plenty on the Forum and YouTube viddys showing how to do it.
I used Gordon Smith in Halesowen, way back. Saw an advert for West Midland Engines from the same premises a few years ago. There is also a place in Redditch used by the Car SOS gang, but to be honest there are probably more of these engineering outfits in the West Midlands than anywhere else.
Grinders will like to supply the bearings as well, but at the end of the day it's your choice, and apart from machining to spec, guarantees are like Unicorn Horns.
Swarfy
